Left Handed Daqload

Wire Bonds and Connections

All of the connections on the LH board seem to work fine, the HV filter (region on the board where C1,C2,R4-R8 are located has all the correct components).

Mini-Sensor

Mini sensor is wire bonded to ABC chip and glued to the HV pad beneath it. Mini-sensor was not correctly cut and is larger than it is supposed to be (shown below)

Sensor should have a bond connecting it to the HVret pad (the outer metal pad). Instead the HV and HVret are shorted together, causing us to measure much larger than expected currents.

Not visible in this picture is a small opening on the mini-sensor outer bias ring, where there is an opening to allow the wire bonder to connect to the aluminum. There are four of these on the mini-sensor, one near each corner

picture would be beneficial

Mini sensor was not cut correctly, and as a result is shorting the HV and HVret ring together. To remedy this the HVret ring should be disconnected from ground. The mini-sensor bias ring should instead be wire bonded to the hybrid ground (the open gold pads next to the ABC130 chip). Remove the HVret connection on the other side of the hybrid and connect that pad to the hybrid ground. This should short the grounds together, and leave the HVret ring disconnected from ground (so that it can sit at -400V with the HV pad). This is shown in the following image

Preliminary Results (2016-10-17)

With the wire bonding changes made to correct the oversized mini-sensor. DAQload seems to be able to hold high voltage now. A series of 3PG tests were run under different conditions (all with dry air running):

Preliminary Results (2016-10-26)

With the ability to remote control the power supplies we can now collect the data necessary for an IV scan of the sensor. This is a preliminary result run on the LH DAQload, mostly useful for showing that we have the ability to get this data

This was run with the temperature at 23 degrees and the dewpoint at -20 degrees. Each step in the voltage is 5V and there is a ten second delay between each step.

Stability Test (2016-11-16)

Found a fix for the root script so that it no longer crashes. Ran a set of tests for the better part of the day with no incidents. Included is a plot of the noise on the bonded channels versus time, showing clear stability over many hours.

This was run with no cooling and no high voltage (hence the high noise level). The temperature range over this time period was between 21.5 and 23.5 degrees but no visible correlation between noise and temperature